1. Field of the Invention
The present invention relates to a gas purge apparatus, a load port apparatus, an installation stand for purging container, and a gas purge method.
2. Description of the Related Art
For example, manufacturing process of semiconductors includes the following technique (bottom purge): a gas purge nozzle is arranged on an installation stand of a load port apparatus and is made contact with a gas purge port provided at a bottom part of a wafer transport container to introduce a purge gas therethrough and clean the inner atmosphere of the wafer transport container by the purge gas.
Upon performing the bottom purge, the purge nozzle is moved toward the purge port to be in contact with the gas purge port provided at the bottom part of the wafer transport container (e.g., see Patent Document 1). At that time, a plurality of the purge ports provided at the bottom part of the transport container has various port connection heights, which may cause the purge nozzle to push up the container and generate a placement failure.
If the transport container is inclined due to the placement failure, handling performance of wafers is adversely affected. For example, the following problems arise: the wafers placed on a shelf inside of the transport container may be damaged due to their inclination; and an insufficient contact between the purge port and the purge nozzle causes a purge gas leak and an outside gas inflow into the transport container.
Patent Document 1: Japanese Patent Laid-Open No.2003-60007